I just wanted to check that this was working ok (using QGIS 1.9 Master). I am a little confused by the different results I get from different data.
The definition of a layer in QGIS using OSGB 1936 / British National Grid (27700) is: +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +towgs84=446.448,-125.157,542.06,0.15,0.247,0.842,-20.489 +units=m +no_defs I have data in MapInfo TAB files that are created in software other than QGIS. When I open these they come in with the following custom projection defined which is different from EPSG 27700 and as such not recognised as it: +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +towgs84=375,-111,431,-0,-0,-0,0 +units=m +no_defs I have data in a shapefile format not created by QGIS. When loaded into QGIS these have the projection defined as a custom projection as shown below which seems to match the EPSG 27700 definition but does not get recognised as 27700: +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012716 +x_0=400000 +y_0=-100000 +ellps=airy +towgs84=446.448,-125.157,542.06,0.1502,0.247,0.8421,-20.4894 +units=m +no_defs Is this the correct behaviour and are all the custom projections giving me the correct results? James James Stott BSc (Hons) MSc | Senior Professional Nicholas Pearson Associates | 30 Brock Street | Bath | BA1 2LN T: 01225 445548 | M: - http://www.npaconsult.co.uk/ http://www.npaconsult.co.uk/http://www.npaconsult.co.uk/about-news.asp http://www.npaconsult.co.uk/terms.asp This Electronic Transmission is intended only for the attention of the addressee. It may contain privileged and confidential information. If you are not the person for whom it is intended, you must not copy, distribute or take any action in reliance on it. If you have received this electronic transmission in error please notify us immediately by telephone, delete the transmission and destroy any hard copies. Nicholas Pearson Associates has used all reasonable efforts to ensure that this message and any attachments are free from viruses. Nicholas Pearson Associates, 30 Brock Street, Bath, BA1 2LN , Tel: +44 (0) 01225 445548, Fax: +44 (0) 01225 312387, Website: http://www.npaconsult.co.uk/ _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
